ExoFlow-ONE EV Labeling Kit for Flow Cytometry (Ruby Red); 25 reactions; The ExoFlow-ONE Ruby Red Gemstone Dye Kit comes with enough labeling reagents for 25 reactions**. Each kit also includes 1.5 mL of silica bead size standards (110 nm – 1300 nm), two of which are fluorescent. The silica beads, sourced from Apogee Flow Systems, are specifically designed to produce a refractive index and light scattering patterns similar to biological particles, enabling more accurate estimation of EV particle size.